K 2500 Truck 4WD V8-454 7.4L VIN J SFI (1997)
Crankshaft Main Bearing: Testing and Inspection
Clean and Inspect
1. Clean the crankshaft with solvent. Do not scratch the bearing journals.
2. Remove all of the sludge from the oil passages with compressed air.
3. Clean the crankshaft bearings. Wipe free of oil with a soft cloth.
NOTE: Replace the clutch pilot bearing located in the end of the crankshaft, anytime a manual transmission or clutch is removed. A worm clutch
pilot bushing will not properly support the manual transmission input shaft when the clutch is released.
4. Inspect the crankshaft for cracks as follows:
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Use the magnaflux method if available.
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Inspect the crankshaft, the crankshaft bearing journals, and the thrust surfaces for scoring, nicks, or damage caused by lack of lubrication.
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Inspect the crankshaft bearings for scoring or other damage. In general, the lower crankshaft bearings, except they #1 bearing, show the
greatest wear and distress from fatigue. Upon inspection, if a lower crankshaft bearing is suitable for reuse, it can be assumed that the upper
crankshaft bearing is also satisfactory. If a lower crankshaft bearing shows evidence of wear or damage, both the upper and the lower
crankshaft bearings must be replaced.
